An unidentified problem has occurred to one of Vietnam’s chief submarine cable systems, compromising the country’s Internet connection in the coming days for some users.

A map of the AAG fiber optic cable that connects Vietnam, Asia and America

The S1H section of the Asia America Gateway (AAG) cable system has conveyed no signal since Saturday morning, the system’s operator said.

A representative from a domestic service provider said the cause has not been determined for certainty so far, but suggested that it could be a shunt fault, which happens when the cable insulation becomes damaged.

Certain Internet users in Vietnam are therefore likely to have sluggish connection to foreign-based services like Gmail and Facebook.

This is the third failure experienced by the AAG this year, with the previous malfunctions on January 6 and May 22.

Eight incidents related to breakage, maintenance and repair have throttled international connectivity from the country via the notorious 20,000-kilometer cable system since early 2017.

The system provides one of Vietnam’s lifeline Internet gateways to the world by linking it with other Southeast Asian countries and with the U.S. across the Pacific Ocean.